Raspberry plant named ‘Korpiko’

ABSTRACT

A new and distinct floricane fruiting red raspberry,  Rubus idaeus  L., variety is described. The variety results from selection among a population of seedlings derived from controlled pollination crossing of the raspberry varieties known as ‘Chilcotin’ (not patented) and ‘Waimea’ (not patented). The fruit of this new variety has an attractive appearance characterized by uniformly large berry size, good fruit firmness, and medium-red fruit color. The new variety is distinguished from others by its high yields of firm, attractive, uniformly sized, large, red berries that ripen in the mid season. The plant exhibits a semi spine-free upright growth habit, of strong vigor. In addition, the plant has displayed resistance to Raspberry Bushy Dwarf Virus (RBDV) under New Zealand conditions. Fruit of the new variety appears suitable for the fresh fruit market. The variety has been named ‘Korpiko’.

Genus and species of plant claimed: Rubus idaeus L.

Variety denomination: Korpiko.

BACKGROUND TO THE INVENTION

The new variety of red raspberry, Rubus idaeus L., was created in thecourse of a planned breeding program carried out at Nelson, Motueka, NewZealand. The parents used to make the cross in 1990, were the varieties‘Chilcotin’ (seed parent) (unpatented) and ‘Waimea’ (pollen parent)(unpatented).

Seed from this cross was grown and the original plant of the new varietywas selected during the 1993-94 summer (Southern Hemisphere) and wasfound to exhibit:

-   -   (a) a semi spine-free upright growth habit of strong vigor,    -   (b) the ability to form attractive large red fruit of good        flavor in high yields on medium length fruiting laterals that        ripen mid season, and    -   (c) resistance to Raspberry Bushy Dwarf Virus (RBDV).

The new variety was first asexually propagated in 1998, at Motueka,Nelson, New Zealand, being reproduced by vegetative cuttings arisingfrom root cuttings. Cuttings developed this way in spring, root within a3–4 week propagation period, and thus plants suitable for field plantingare then ready in autumn of the same year. The resulting plantspropagated true to type, demonstrating that the characteristics of thenew cltivar are stable and are transmitted without change throughsucceeding generations. Since 2000, ‘Korpiko’ has been asexuallypropagated in vitro via tissue culture methods. The cultivar haspropagaated true to type via these means.

SUMMARY OF THE INVENTION

The new variety was selected from a population of seedlings derived fromcrossing the raspberry varieties known as ‘Chilcotin’ (not patented) and‘Waimea’ (not patented). The new variety was assigned the breeder code,90311BF-7 (subsequently coded HR6 at the advanced selection stage). Thenew variety has since been named ‘Korpiko’.

The new variety was tested and evaluated during the years 1996 to 2005at Nelson Region, New Zealand (41.10°S, 172.97°E). The new variety hasalso been observed in test plots in Washington State, United States ofAmerica (USA).

When compared to the parent ‘Chilcotin’, the new variety was found tohave larger, more conical shaped fruit of similar color, the largerfruit resulting in higher yields. ‘Korpiko’ is further distinguishedfrom ‘Chilcotin’ by having fewer spines on canes.

When compared to the parent ‘Waimea’, the new variety exhibits fruitthat are brighter red in color, that are larger and more conical inshape. ‘Korpiko’ also produces significantly higher cane numbers than‘Waimea’ resulting in higher potential productivity and has more spineson canes.

TABLE 1 Comparison of fruiting and shelf life performance. 2003/04season 2005/06 season Berry Berry Yield¹ weight Shelf Yield¹ weightShelf Variety (T/ha) (g) life² (T/ha) (g) life² ‘Tadmor′ (U.S. 25.9 4.536 13.7 4.7 50 Plant Pat. No. 14,036) ‘Korpiko′ 14.8 4 45 17.2 5.3 27‘Tulameen′ 17.1 4.1 63 12.9 4.2 76 (not patented) ‘Motueka′ 21.3 2.715.3 3.8 (U.S. Plant Pat. No. 14,035) ‘Moutere′ 17.4 3 63 14.2 4.5 48(U.S. Plant Pat. No. 17.744) ‘Korere′ (co- 19.5 2.8 30 13.2 3.8 48pending U.S. Plant Pat. application No. 12/214,361) ¹Hand-picked ²Mean(10 berries × 3 reps × 3 harvests) cumulative percentage of berries withrot caused by Botrytis after 72 holurs on the shelf at ambienttemperatures (15-20° C.).

Berries of the new variety are suitable for consumption as mid season,high-grade fresh fruit.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying photographs show typical specimens of the plant,foliage and fruit of the new variety as depicted in colors as nearlytrue as is reasonably possible to make the same in a color illustrationof this character. The photographs were taken on mature plants in NelsonRegion, New Zealand and Washington State, USA.

FIG. 1 shows fruit of the variety ‘Korpiko’.

FIG. 2 shows a sample of individual fruit of the variety ‘Korpiko’alongside a scale indicating fruit size.

FIG. 3 shows close-up views of tyypical individual fruit of the variety‘Korpiko’ on a 1 cm×1 cm grid.

FIG. 4 shows a close-up view of a fruiting lateral, including fruit, ofthe variety ‘Korpiko’ on the plant.

FIG. 5 shhows the leaf and shoot tip of a fruiting lateral of thevariety ‘Korpiko’.

FIG. 6 shows a primocane tip of a cane of the variety ‘Korpiko’; view isof the upper and lower surface of the leaves.

FIG. 7 shows a floricane leaf of the variety ‘Korpiko’; view is of theupper and lower surfaces.

FIG. 8 shows a plant of the variety ‘Korpiko’ in the field; view is ofthe post-flowering, early fruit set stage.

FIG. 9 shows a fruiting plant of the variety, ‘Korpiko’ in the field;the large fruit size, high productivity, and the productive, mediumlength fruiting laterals are displayed.

DETAILED DESCRIPTION

Horticultural terminology is used in accordance with UPOV guidelines forrasoberry. All dimensions in millimeters, weights in grams (unlessotherwise stated). Where a colour reference is given these refer to TheR.H.S. Colour Chart, The Royal Horticultural Society, London, 4thEdition, 2001. The specimens described were grown at Nelson, NewZealand, and in Washington State, USA.

Environmental data for the New Zealand growing area demonstratesconditions in spring and early summer (equating to the harvest periodfor the cultivar) as follows:

Spring (September/October); mean daily temperature in the range 10–12°C. (mean daily minimum 5.8° C., mean daily maximum 16.5° C.).

Early summer (December/January); mean daily temperature 16.8° C. (meandaily minimum 11.1° C., mean daily maximum 22.4° C.).

A cool temperate area, frost conditions are typically experienced inwinter, with the lowest winter air temperature unlikely to be colderthan −6° C. Average annual rainfall is approximately 1125 mm.

-   Plant and foliage: plants exhibit a strong and medium upright growth    habit (FIGS. 8 and 9). Mature plant height is commonly in the range    2000 mm to 2500 mm, although this may vary with the growing    conditions. Strong vigor is exhibited and internode length is    typically long in the range 110–130 mm. Plants have many young    shoots; canes have many spines near the base and few near the top of    mature canes. Spines (prickles/thorns) are sparse, particularly on    the upper cane section and are small on mature canes (typically    approximately 1 mm long), but may be denser and longer on juvenile    canes. Plants have been observed to be less spiny compared with some    other commercial varieties, for instance, ‘Marcy’ (not patented).    Spine color is dark (near purple N79A). Canes are pubescent    indicating the presence of gene H. Canes typically show light    brown-tan coloration (near Greyed-orange 174A and Grey-brown 199B)    in winter. During the growing season some purple coloration (near    Red-purple 59A) is evident on the sun-exposed side of the cane.    Young shoots are erect and are near Yellow-green 144A in color.    Fruiting laterals are medium long typically 600–800 mm in length.    The leaves are compound, moderately crinkled, flat and moderately    dull, with strong silver coloration on the leaf underside. (FIGS. 6    and 7). The number of primocane leaflets per internode is both three    and five. The base of the terminal leaflet is rounded in shape and    typically averages 80 mm in diameter and 100 mm in length. The    coloration of the upper surface of the leaf is green (near    Yellow-green 146A), the under side being markedly lighter in    coloration (near Greyed-green 191A). While the leaves do not have    distinguished marginal or vein coloration, the venation has    noticeable rises and falls, and the leaf margin is typically    serrate. The leaf petiole typically averages approximately 105 mm in    length and 2.5 mm in diameter. It is near Yellow-green 144B in    color. The fruit is borne on the previous year's growth. The    fruiting laterals are medium long in length, commonly measuring    500–700 mm, and are weakly ascending and horizontal when fruit has    ripened. Fruit presentation at harvest time is excellent and well    suited to hand-picking.-   Inflorescence: White flowers are borne on short slender pedicels    with sparse spines (thorns/prickles). At Nelson Region, New Zealand    the date bud burst commences is approximately 8 September, with    fifty percent of buds burst by mid-late September (approximately 22    September). The time of bloom is mid season for a summer-fruiting    raspberry, with peak flowering around mid November. Flowers are    numerous and borne on a paniculate inflorescence. Typically there    are five petals, elongated ovate in shape with a rounded apex and    flat base. The petals average approximately 7.1 mm in length and 3.4    mm in width. They are typically smooth in texture, have a smooth    margin and are near White 155C in color. The pedicel length averages    approximately 17.0 mm long. However, the more basal the pedicel the    longer it commonly becomes with pedicel lengths up to about 50 mm    being observed. The pedicel averages approximately 1.1 mm in    diameter and is near Yellow-green 144A in color and has weak    anthocyanin coloration on the sun-exposed side. A typical king    flower diameter is approximately 29 mm (from sepal tip to sepal tip    i.e. the widest part of the flower). The flowers are predominantly    borne singly, although sometimes in clusters of two or more.    Terminal branch flower clusters frequently consist of two flowers    and basal flower clusters may number three to five. The flowers have    no discernible fragrance. Five sepals are present. These are green    in coloration (near Yellow-green 144A on the bottom and near Green    138C on top) and measure approximately 15 mm in length from base to    tip. The reproductive organs are typical for flowers of Rubus idaeus    L.; the stigmas average approximately 95 in number and are near    Yellow-green 145C in color; there are approximately 90–95 stamens    the filaments which are near White 155D in color and average 4.4 mm    in length. Anthers are brown and (depending on maturity) near Brown    200D in color.-   Harvest: Fruit commences ripening in mid December in New Zealand.    The typical start date for picking the new variety is 13 December.    Fifty percent of the harvest is typically completed by 28 December,    and the main harvest period is complete by mid January    (approximately 18 January). ‘Korpiko’ is not suitable for harvest by    machine due to the moderately strong force required to dislodge the    berry from the receptacle. ‘Korpiko’ is recommended for mid season    production for fresh market fruit. The variety may also be suited to    long cane production systems due to its high quality fruit and    suitability to fresh markets.-   Fruit: Fruit is produced on previous year's cane in summer. Berry    size is large. The average berry weight is approximately 4.5 g;    individual fruit ranging between 4–6 g in weight (Table 1). Fruit    shape is conical; on the basis of fruit length to width ratio, fruit    is much longer than broad (FIG. 3). On average berries are 25 mm    long and 20 mm wide at the widest point. Fruit color is medium red;    external color near Red-46A, internal color near Red 46A. Fruit    color of ‘Korpiko’ fruit has been observed to differ to that of    another commercial red raspberry variety, ‘Skeena’ (not patented),    which has medium dark red fruit. The fruit skin of ‘Korpiko’ fruit    shows medium to high glossiness as a result of hairs present.    Attractive large conical shaped fruit and the presence of fine hairs    on the fruit skin are distinctive features of the new variety. Fruit    drupelet size has been observed to be medium compared with drupelet    size of fruit of another commercial red raspberry variety, ‘Glen    Ample’ (not patented) which are large. Drupelets number typically 95    and are quite large, typically 4.5 mm in diameter. Fruit size is    uniformly large through the harvest maturity period. The berries are    medium firm and of good raspberry flavor. The seeds average 3.0 mm    long and 1.6 mm wide, and are near Greyed-orange 164D in color when    dry. Seed numbers per fruit average 95 and weigh on average 0.14 g    per fruit (or average 1.5 mg individually). Fruit quality is largely    due to the fruit having a firm and fleshy-texture with good flavor.    ‘Korpiko’ fruit has been observed to have a good shelf life in    Nelson Region, New Zealand (Table 1). Fruit shelf life appears    improved over the commercial varieties ‘Marcy’ (not patented),    ‘Skeena’ (not patented), and ‘Tulameen’ (not patented). Yield is    high, typically in the range 14–18 T/ha equivalent (Table 1).-   Pest and disease resistance: The plant does not seem to be    susceptible to yellow rust (Phragmidium rubi-idaei) and appears    resistant to Raspberry Bushy Dwarf Virus (RBDV). Since the selection    of this clone in 1993–94 numerous tests for RBDV have been carried    out on ‘Korpiko’ in New Zealand using ELISA, but on no occasion has    the virus been detected in spite of high infection pressure. From    this we suggest that ‘Korpiko’ is likely to be resistant to the    common strain of RBDV found in New Zealand. Resistance to aphids is    unknown.-   Geographical adaptation: Observations indicate that the variety is    well-suited to production in regions that offer a medium amount of    winter chill, for example, ‘Korpiko’ performs well in the cool    temperate region of Nelson, New Zealand under standard management    practices for commercial raspberry production. Initial indications    are that ‘Korpiko’ also performs well in USDA Plant Hardiness zones    8–10 (published as the 2003 US National Arboretum “Web Version” of    the USDA Plant Hardiness Zone Map USDA Miscellaneous Publication No.    1475, Issued January 1990).

1. A new and distinct red raspberry plant as herein illustrated anddescribed.